This invention is directed to a multiple device control apparatus for a multiple inputted load apparatus and particularly to a step-type controller for a water heater or like load means having a plurality of selectively actuated heating elements.
Multiple input apparatus may include a plurality of individual actuated load inputs for controlling the state of or conditioning the load apparatus by sequential and selective actuation of such plurality of inputs. For example, water heating apparatus may be constructed with a plurality of individual heating elements or units rather than one single modulated element for varying the thermal energy inputted into the stored water. The heat input may be conveniently controlled by varying of the number of the heating elements which are activated at any given time. The actuation of the heating elements may be varied depending upon the temperature of the stored water, the time of day, the anticipated usage, the recovery rate requirements and any other factor or condition which can effect the heat input requirement. In such a system, it may be desirable to provide for particular types of sequential operations of the load devices. This in turn requires proper sensing and monitoring of status of all such load input devices as well as the various control factors, and then controlling the load or element activations in accordance with the predetermined relative sensed and monitored conditions.